Forensic scientists listen to what bones have to say Evidence in case of Harrison death is pursued in labs

December 07, 1996|By Frank D. Roylance | Frank D. Roylance,SUN STAFF

In life, Susan Hurley Harrison cared about her appearance and spent thousands of dollars on extensive dental work.

In death, that dental work enabled investigators to confirm that a skeleton discovered last week in the woods of Frederick County was hers.

Now forensic scientists at the state medical examiner's office in Baltimore have an even tougher task: searching the remains for clues about Harrison's death.

Or, as Dr. Ann Dixon, deputy chief medical examiner, said yesterday, "working to see what [the bones] are trying to tell us."

Dixon declined to discuss specifics of the Harrison case. But she described skeletal remains -- with no soft tissue remaining -- as "the ultimate challenge" for forensic scientists.

Bones can reveal signs of injuries and clues to when those injuries occurred. X-rays might reveal fragments of metal -- from a bullet or knife. "Such things do have a way of burying themselves in a piece of bone without too much indication externally," Dixon said.

"If one is looking for drugs in an individual, one hopes to have blood or other material -- solid organs. Beyond that, it becomes perhaps not futile, but exceedingly difficult."

Some poisons, such as arsenic, can persist in bones for years, said Dr. Dennis C. Dirkmaat, a consulting forensic anthropologist and assistant professor of anthropology at the Mercyhurst Archaeological Institute, in Erie, Pa.

Even drug evidence may persist in the soil beneath a skeleton. "Levels of cocaine may be evident in a soil analysis . . . longer

than one would think, longer than a couple of years," he said.

For these and other reasons, he said, it's critical for investigators to gather as much information as they can from the site where a skeleton has been found, even before the bones are moved.

The position of the body, the orientation of the bones relative to each other, relative to weapons, rocks and other physical evidence or to leaf layers can provide important clues to the time and manner of death.

The hyoid bone, for example, is a small bone in the neck that is often broken during strangulation. But untrained investigators, Dirkmaat said, sometimes mistake it for a stick and leave it

behind.

Back in the lab, close examination of damage or injuries to bones -- such as ribs broken by a blow or nicked in a knifing -- can reveal whether they occurred at death, earlier in life, or after the bones were clean and dry.

The first objective of forensic investigators is usually to establish identity. Harrison's remains were identified by Dr. Bernard A. Levy, chief forensic dentist for the medical examiner's office and professor in the department of oral pathology at the University of Maryland at Baltimore.

Harrison was 52 when she disappeared in 1994. Although police initially thought the remains were from a woman in her 20s or 30s, Levy saw quickly she had been older.

After looking at the skull and teeth, he said, "it was very easy for me to conclude we were dealing with probably a 45- to 55-year-old Caucasian female who had a consciousness of good dental care and hygiene."

"Teeth are a pretty good indicator of age," he said. "In the earliest ages, up to 21, they are very accurate because teeth are erupting at different times. After 21, the range of estimates gets wider and wider."

For people in their 40s and 50s, age is revealed more by bone loss from periodontal disease and tooth wear from eating.

Gender and race, too, can be determined by bone and tooth structure. "Generally, females have finer bone structure and smaller bones than males," Levy said. And while one can be fooled, "the actual shape of the jaws varies from race to race, and some have different shapes of certain teeth."

In the end, though, dental work clinched Harrison's identification.

Her dental records were filed two years ago with the National Crime Information Center. "We had a record of all her restorations and all recent X-rays" -- details not always available, Levy said.

The dental remains suggested "somebody who was willing to spend time and money having their mouth restored well," he said. "All of the metallic work that might have been there was covered with porcelain to make it look like tooth. Her teeth were beautifully capped."

Matching the records with new X-rays made this "a very easy, straightforward, positive ID," Levy said. With two other medical examiners at his side, the whole process took "about a half-hour."

By contrast, his identification of Holly Ann Blake, a 28-year-old Pennsylvania waitress who was strangled in Carroll County in 1991, took much longer.

Blake's killer burned her remains for 12 hours and then threw them in a river.

Levy spent seven hours at a lab table reassembling bits of jawbone and tooth roots with modeling clay before he had enough to compare with Blake's dental X-rays. It took an unusual pattern in her sinus bones to clinch the ID.

James VanMetre III was eventually convicted of the crime. But a botched prosecution caused the verdict to be thrown out. VanMetre is in jail in Pennsylvania on other charges.

Determining how Susan Harrison died will require looking beyond her head and teeth.

Although her remains were missing several teeth, those appeared to have fallen out after decomposition.

"Nothing I saw gave any suggestion as to the cause of death," Levy said. "From what I saw she could have wandered off into the woods" and died.